California rains put spotlight on atmospheric rivers

California has no mighty rivers like the Mississippi, but rivers of a kind are flooding the state. Since the new year, more than a meter of precipitation has fallen in some places, unleashing floods, triggering landslides, and, last week, bringing the emergency spillway of the Oroville Dam, the tallest in the nation, to the brink of failure. The seemingly endless string of storms has also been a boon, because after five crippling years, drought has been vanquished from all but the southern corners of the state. It’s all because of atmospheric rivers: long, narrow ribbons of water vapor rushing across the sky.